Disk Event ID 157 and 58 in Hyper-V VMs

[Billm]

The Backups appear to be working, but I am seeing the following event log warnings in the Virtual Machines.
Event ID 157: Disk 1 has been surprise removed.
The Disk number varies depending on the number of actual disks.
Additionally on one of the VMs I get
Event ID 58: The disk signature of disk 1 is equal to the disk signature f disk 0.
During normal operation there is no disk 1. My google searches indicate it is a product of VSS.

OS is Server 2012 R2 Datacenter with VMs running 2012 R2 Standard.

[Stuart]

Hi Bill,

It's Stuart here from the BackupAssist team.

These events have been mentioned on many Microsoft forums and blogs which all indicate that they can be ignored as long as there is no further problems being logged around the events.

https://blogs.msdn.microsoft.com/virtual_pc_guy/2015/04/03/hyper-v-and-event-id-157-disk-x-has-been-surprise-removed
https://community.spiceworks.com/topic/463141-windows-server-backup-causing-eventid-157-disk-n-has-been-surprised-removed
https://social.technet.microsoft.com/Forums/windowsserver/en-US/70d8cbee-a189-4555-80c1-3b19ebb51d0c/error-in-virtual-machine-event-log-disk-1-has-been-surprise-removed?forum=winserverhyperv

Do you have any issues with the backup itself or are they running as expected?